Self-cleaning tank washer

ABSTRACT

Structure for cleaning the interior of a milk transport tank which is sufficiently self-cleaning to remain in place inside the tank when the latter is filled with milk, and yet which is configured for quick and easy removal from the tank interior.

United States Patent [1 1 Metz [451 July 23,1974

[5 1 SELF-CLEANING TANK WASHER 21 Appl. No.: 355,910

[52] US. Cl. 134/104, 134/167 R [51] Int. Cl. B08b 9/08 [58] Field of Search 134/104, 166 R, 167 R,

[56] References Cited UNITED STATES PATENTS 10/1940 Rudigier 134/167 R 12/1971 Baldwin 134/167 R Primary Examiner-Robert L. Bleutge Attorney, Agent, or FirmEdward L. Brown, Jr.

[5 7] ABSTRACT Structure for cleaning the interior of a milk transport tank which is sufficiently self-cleaning to remain in place inside the tank when the latter is filled with milk, and yet which is configured for quick and easy removal from the tank interior.

2,045,752 6/1936 Butterworth 134/168 R X 14 Claims, 6 Drawing Figures 3a r 40 a4 a4 46 r 42 42 42 f 48 PATENTED 3 1974 3.825.022

sum 2 [IF 2 SELF-CLEANING TANK WASHER This invention relates to structure for cleaning, by flow of cleansing fluid from an external source, the interior of mobile transport tanks that carry milk or other edible fluids or other liquids which must not be'contaminated, and thereby require a high degree of cleanliness of the tank interior.

Transport tanks for milk or like liquid requiring a high degree of cleanliness conventionally have an ac cess opening or manhole in the top which allows access for workmen to descend into the interior and manually spray down and clean the tank. Usually the tank is of elongated cylindrical configuration with a drain spigot at one end for draining the cleansing fluid used.

Ideally, the cleaning process can be carried out faster, more economically and efficiently with less manual labor by use of structure inside the tank interior which completely sprays down the interior upon being fed with cleansing fluid from an external source. More efficient cleansing fluids, i.e.', hotter and/or more caustic or acidic, can thenbe used and be used for longer time periods to assure complete saturation of the interior, since human contact with the cleansing fluid is eliminated.

Despite these obvious advantages, however, use of such structure to spray down the tank interior has certain practical difficulties which have prevented application of automated cleaning systems where an extremely high degree of cleanliness is required.

Due to the disproportionate longitudinal dimension of semi-trailer tanks, the use of a single rotating head creates an inefficient systemQThe end areas of the tank receive much less exposure to the cleansing fluids than does the center area of the tank. It is therefore most efficient to use a system which has multiple spray units running the length of the tank.

If the automated washing system is an installation of u permanent piping inside the tank, it must be accomplished with great care to avoid formation of cracks, crevices or low spots which will collect bacteria, cleaning fluids or the like, and which can be extremely difficult to purge and thoroughly remove from the tank. For instance, great care must be taken in attaching the piping to the interior. Welding is the only feasible method of permanent attachment that may not create crevices and the like, yet such weld joints themselves must be carefully built up to avoid small cracks and crevices that are extremely difficult to clean. Additionally, repair of the piping is highly expensive in such permanently installed structure.

A piping system that can be left in the tank or removed at the option of the user has not been feasible for various reasons. The piping must necessarily be in sections small enough in lengthto be inserted through the access opening. The resulting joints defined between the separate conduits of the piping present zones of cracks, sharp bends, and crevices that are difficult to clean. Furthermore, to minimize liquid-collecting zones, such removable cleansing structure has been 2 Accordingly, it would be highly advantageous to provide a permanent cleaning structure which is sufficiently self-cleaning so as to allow it to remain in the tank after cleaning and to eliminate the need for a second, manual cleaning of the cleaning structure.

It is therefore the primary object of the present invention to provide structure for cleaningthe interior of such a tank which is made in removable sections and yet which is sufficiently self-cleaning to remain in the tank after it is filled with milk or like liquid.

One object of the invention is to provide coupling means for interconnecting conduits used in the structure which are self-purging to allow complete cleaning d-ue just to the flow of the cleansing fluid through the conduits.

Another object of the invention is to provide structure for cleaning the tank interior which utilizes rotary spray headers that efficiently saturate the tank interior with minimum pressurization of cleaning fluid delivered to the headers, and which reduces the amount of piping required to the cleaning structure.

Another object of the invention is to provide a permanent cleaning system in the tank that can also be used in conjunction with air pressure to mix the milk while in the tank.

These and other objects and advantages of the present invention are specifically set forth in or will become apparent from the following detaileddescription of a preferred embodiment of the invention when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a longitudinal cross-section of a mobile transport tank equipped with structure of the present invention, with a source of cleansing fluid shown schematically;

FIG. 2 isa transverse cross-sectional view of the arrangement of FIG. 1;

FIG. 3 is a fragmentary elevational view of the structure of the present invention with portions broken away to reveal details of construction;

FIG. 4 is a transverse cross-sectional view of one of the supports and conduit held thereby;

FIG. 5 is an enlarged cross-sectional view taken along lines 5 5 of FIG. 3; and

FIG. 6 is an enlarged cross-sectional view taken along lines 6-6 of FIG. 3.

Referring now more particularly to the drawings,

there is illustrated a mobile transport tank 10 of elonto the tank wall and platform 12 to define an opening Structure, generally denoted by the numeral 22, is providedwithin the tank interior to direct cleansing fluid to all parts of the tank from an external source 24. The cleaning structure 22 includes a vertical riser 26 which has a threaded external end 29 adapted to be connected to source 24. Riser 26 extends downwardly through opening 20 in sealed relationship to the tank interior by virtue of a compressible, elastomer sealing member 28 and its companion sealing nut 30. A plurality of apertures 32 in the riser located closely below sealing member 28 allows cleansing fluid to escape from the riser and purge the interior of ferrule 14 and the exterior of riser 26 to assure complete cleaning of all portions below sealing member 28. Upon unscrewing nut 30, the riser will be released for easy removal through opening 20.

Riser 26 connects to a pair of fluid carrying conduits 34 and 36 which extend longitudinally and generally .horizontally from their tee connection with riser 26.

Ends of the conduits 34 and 36 are connected to conventionally structured rotating spray headers 38 and 40. These headers are operable by fluid flow therethrough' which spray the cleansing or flushing fluid about the interior of the tank in a uniform saturating manner. A plurality of supports 42 are permanently affixed to the interior tank wall by smooth weld joints 43 and have eyelet openings 44 for loosely receiving conduits 34 and 36 to hold same in their horizontal posit1on.

Similar coupling means are provided between the riser 26, conduits 34, 36, and the spray headers 38 and 40 to define loose fitting joints which couple the cleaning system 22 together. Between riser 26 and conduits 34, 36 is a tee fitting 46 which has enlarged diameter ends that receive the adjacent ends of riser 26 and conduits 34, 36 in a loose tolerance fit. Holes 47 in each of these enlarged ends align with corresponding holes 27, 35, 37 in the ends of the riser and conduits. Similarly, between the adjacent ends of spray headers 38, 40 and conduits 34, 36 are elbow fittings 48 which have holes 49 aligning with holes 50 in the remote ends of conduits 34,36.

At each of these joints the coupling means further include a pin, in the form of a spring clip 52, that has a straight segment 54 loosely extending through the correspondingly aligned holes in the coupling, as for example 27 and 47 of FIG. 5. A curved segment 56 (FIG. 4) of the clip 52 frictionally engages the outer surface of the corresponding fittings 46 to intersecure the components of the coupling. Clips 52 are metallic or high impact plastic having sufficient resiliency to allow quick and easy insertion and removal for ease in assembly and dismantling. Straight segments 54 are relatively loose within their corresponding holes to allow relatively free fluid flow therethrough. As shown by the arrows in FIG. 5, which indicate the fluid flow through the coupling, tolerance of the coupling parts assures flow of cleansing fluid through the joints to completely purge and clean same.

Similar spring clips 52 with straight and curved segments 54 and 56 loosely extend through aligned holes 58 and 60 (FIG. 4) in the conduits 34 and 36 and the pipe supports 42, to hold conduits in position. Again, the relative diameter of the spring clip and the loose tolerance of the conduit in the support 42 allows free flow of cleansing fluid therethrough to purge the zone between the conduits and the interior surfaces of the support eyelets 44.

Referring to FIG. 3, spray header 40 has a central vertical pipe 62 extendingdown from the base 61, the lower end of which is disposed adjacent the upper end of elbow 48. A pair of generally small diameter tubes 64 extend outwardly from the ends of the header and have apertures 66 for spraying the fluid about the tank 4 interior. Preferably, tubes 64 are disposed so that fluid emanating from their apertures is directed toward the top corners 68, 70 of the tank for the most efficient spray cleansing. Tubes 64 are attached to the base 61 of header 50 by similar spring clips 52.

The spray headers are connected in rotatable relationship to elbow fittings 48 as best illustrated in FIG. 6. A flange 72 at the lower end of pipe 62 operably rests on the enlarged end of elbow fitting 48 with a low friction washer 74 disposed therebetween. Washer 74 is formed of material having a low co-efficient of'friction. A collar 76 loosely surrounds the ends of the elbow and pipe, and presents a shoulder 78 that is operably engageable with flange 72 through another low friction washer 80. Collar. 76 has openings that align with corresponding openings in the enlarged upper end of elbow 48. Again, spring clips 52 are provided with straight segments 54 extending through these aligned openings to operably join pipe 62 to the elbow 48 while allowing free fluid flow through the joint and especially inside collar 76 to purge-this zone. The curved segment of the clips engage the outer surfaces of collars 76 to hold the assembly in position.

The structure is assembled quickly and easily by bringing the several components in through the top access opening 11 in the tank. In this connection, the lengths of conduits 34 and 36 are sized to allow easy maneuverability through the access opening. The conduits 34 and 36 are slipped through the support eyelets 44 and pinned thereto by clips 52. Similarly, the elbow and tee fittings 48 and 46 respectively are pinned to the conduits, and spray headers 38 and 40 are pinned in rotatable relationship to the elbows 48. Riser 26 is then lowered through opening 20 andpinned to tee fitting 46. Lastly, sealing member 28 and nut 30 are assembled onto the riser 26 and ferrule 14, andexterior end 29 of the riser is in position to be connectedto source 24. Disassembly and removal of structure 22 is easily accomplished by reversing the above procedure.

To effect cleaning of the tank interior, cleaning fluid flow under pressure is directed into riser 26 and conduits 34, 36.to spray headers 38, 40. The force of fluid flow causes rotation of the headers as the fluid is discharged through the arms into the tank interior. The fluid flow through the connecting joints completely purges and cleanses same as cleaning of the tank continues. The fluid is drained from one end of the tank, and a rinse solution can then be directed through the cleansing structure. During drainage of liquid from the tank interior, it will be noted in FIG. 2 that there is no impediment to drainage flow along the bottom lowermost portion 84 of the tank, since the location of supports 42 is offset from the transverse centerline of the tank, positioning structure 22 completely out of the drainage path.

The cleaning structure 22 and joints between the components thereof are sufficiently self-cleaning that no manual cleaning is required. Thus, the structure can be retained in the tank after the latter is filled with milk or like liquid. Sealing of riser 26 is accomplished simply by screwing a cap (not shown) onto end 29.

By retaining structure 22 inside the tank, it has a second use in agitating the milk for complete mixing of the butter fat. By forcing pressurized air through structure 22, a rolling action of the liquid results, the rolling action again enhanced by the offset positioning of supports 42. I

. systems to remain in the tank during transit; the system can be easily removed with the exception of the sup ports 42.

Various modifications'and alterations to theembodiment described above in detail will be apparent to those skilled in the art. Accordingly, to the extent that such modifications are covered vby the appendaged claims upon a fair' and reasonable interpretation thereof, the foregoing description should be considered exemplary in nature and not as limiting to the scope and spirit of the invention as defined by the claims.

Having described the invention with sufficient clarity that those skilled in the art may make and use it, what is claimed is new anddesired to be secured by letters patent, is:

1. Self-cleaning structure for cleansing the interior of a mobile transport tank having an access opening in the top thereof and adapted to carry milk or like liquid, by use of cleansing fluid from an external source, said structure comprising:

a riser adapted to be connected to the external source of cleansing fluid, extending downwardly into the interior of the tank;

conduit means communicating with said riser and extending longitudinally in a generally horizontal disposition along a substantial length of the tank including sections of a length facilitating insertion and removal thereof through the access opening;

support means permanently'and sealingly affixed to the interior wall of the tank for removably receiving said conduit means to hold the latter in a generally horizontal position; a

spray means positioned along the conduit means having apertures therein for spraying the cleansing fluid about the interior of the tank; and

coupling means defining joints between the riser and the conduit means sections, for releasably coupling said conduit means to to said riser in a relatively loose tolerance allowing free flow of the cleansing fluid through said joints to completely purge and clean the joints whereby said structure is sufficiently self-cleaning to remain in the tank after the latter is filled with milk or like liquid.

2. Structure as set forth in claim 1, wherein the coupling means includes first and second end members, the first end member having an inside diameter sufficiently larger than the outside diameter of the second end member to allow flow of fluid therebetween; aligned holes in the first and second end members and pin means loosely fitting in said holes for releasably holding the coupling together.

3. Structure as set forth in claim 2, wherein said conduit means includes sections extending horizontally in opposite directions from said riser to present opposite ends disposed remotely from the riser, there being a spray header disposed at each of said opposite ends of the sections for spraying cleansing fluid about the interior of the tank. a

4. Structure as set forth in claim 1, wherein said coupling means includes a fitting between said riser and conduit means sections, and between said conduit means sections and the spray means; the fitting having larger diameter ends for loosely receiving corresponding ends of said riser, said conduit means and said spray means, said ends of the fittings and corresponding ends of the riser, conduit means and header having aligned holes therein; and pins having straight segments loosely fitting in saidaligned holes to couple said fittings to said riser, said conduit means and said header.

5. Structure as set forth in claim 4, wherein said fitting between said riser and said conduit means is a tee fitting having three enlarged ends receiving adjacent ends of said riser and said conduits.

6. Structure as set forth in claim 1, wherein said coupling means includes a fitting between said riser and conduit means sections, and between said conduit means sections and the spray means; the fitting having larger diameter ends for loosely receiving corresponding ends of said riser, said conduit means and said spray means, said ends of the fittings and corresponding ends of the riser, conduit means and header having aligned holes therein; and pins having straight segments loosely fitting in said aligned holes to couple said fittings to said riser, said conduit means and said header, said pins having curved segments frictionally engaging the outer surfaces of said fittings to hold said pins in said aligned holes.

'7. Structure as set forth in claim 1, including means for releasably securing said conduit means to said support means to hold the self-cleaning structure in position.

8. Structure as set forth in claim 7, wherein said support means is configured to loosely surround said constraight segments loosely fitting in said aligned holes yet allowing fluid flow therethrough.

9. Structure as set forth in claim 7, wherein said support means is configured to loosely surround said conduit means, said conduit means and support having aligned holes therein, and means securing the conduit means to the support means in the form of pins having straight segments loosely fitting in said aligned holes yet allowing fluid flow therethrough, and curved segments frictionally engaging the outer surfaces of said supports to hold said pins in said holes.

10. Structure set forth in claim 1, wherein said supports are disposed to hold said conduit means in offset relation to a transverse centerline of said tank.

11. Structure as set forth in claim 1, wherein the coupling means includes first and second end members, the first end member having an inside diameter sufficiently larger than the outside diameter of the second end member to allow flow of fluid therebetween; vertically aligned holes in the first and second end members and pin means loosely fitting in said holes for releasably holding the coupling together and allowing the conduit means to drain through the lower most holes.

12. In combination with a mobile transport tank having an access opening in.the top thereof and adapted to carry milk or like liquid, self-cleaning structure for cleansing the interior of the tank by use of cleansing fluid from an external source, said structure comprising:

a riser adapted to be connected to the external source of cleansing fluid and extending downwardly, into the interior of the tank;

conduit means communicating with said riser and extending in a generally horizontal disposition to distribute the cleansing fluid along a substantial length of the tank with a remote end of the conduit means spaced from said riser,- said conduit means comprising sections of a length facilitating insertion and removal thereof through the access opening;

support means permanently affixed to the interior wall of the tank and removably receiving said conduit means to hold the latter in said generally horizontal disposition thereof; and

coupling means for defining a joint between said conduit means and said riser, for releasably coupling said conduit means to said riser in a relatively loose tolerance allowing free flow of the cleansing fluid through said joint to completely purge and clean the joint whereby said structure is sufficiently selfcleaning to remain in the tank afterthe latter is filledwith milk or like liquid.

13. Structure as set forth in claim 12, wherein said conduit means is disposed with a remote end spaced from said riser, there being a spray header coupled to said remote end of the conduit means and in communication therewith, said header being rotatable in a generally horizontal plane in response to flow of cleansing fluid thereto from said conduit means and having apertures therein for spraying the cleansing fluid about the interior of the tank.

14. Structure for cleansing the interior of a mobile transport tank having an access opening in the top thereof and adapted tocarry milk or like liquid, by use of cleansing fluid from an external source, said structure comprising:

a riser adapted to be connected to the external source of cleansing fluid and extending downwardly into the center of the tank in sealed relationship thereto to deliver cleansing fluid to the interior;

conduit means coupled to and communicating with said riser and extending in opposite directions along a substantial length of the tank with opposite remote ends of the conduit means spaced from said riser, said conduit means comprising sections of a length facilitating insertion and removal thereof through the access opening;

support means adapted to be permanently affixed to the interior wall of the tank and removably receiving said conduit means to hold the latter in said generally horizontal position thereof; and

a pair of spray headers coupled to said remote ends of the conduit means and in communication therewith, said headers being rotatable in a-generallyv horizontal plane in response -to flow of cleansing fluid thereto from said conduit means and having apertures therein for'spraying the cleansing fluid about the interior of the tank. 

1. Self-cleaning structure for cleansing the interior of a mobile transport tank having an access opening in the top thereof and adapted to carry milk or like liquid, by use of cleansing fluid from an external source, said structure comprising: a riser adapted to be connected to the external source of cleansing fluid, extending downwardly into the interior of the tank; conduit means communicating with said riser and extending longitudinally in a generally horizontal disposition along a substantial length of the tank including sections of a length facilitating insertion and removal thereof through the access opening; support means permanently and sealingly affixed to the interior wall of the tank for removably receiving said conduit means to hold the latter in a generallY horizontal position; spray means positioned along the conduit means having apertures therein for spraying the cleansing fluid about the interior of the tank; and coupling means defining joints between the riser and the conduit means sections, for releasably coupling said conduit means to to said riser in a relatively loose tolerance allowing free flow of the cleansing fluid through said joints to completely purge and clean the joints whereby said structure is sufficiently self-cleaning to remain in the tank after the latter is filled with milk or like liquid.
 2. Structure as set forth in claim 1, wherein the coupling means includes first and second end members, the first end member having an inside diameter sufficiently larger than the outside diameter of the second end member to allow flow of fluid therebetween; aligned holes in the first and second end members and pin means loosely fitting in said holes for releasably holding the coupling together.
 3. Structure as set forth in claim 2, wherein said conduit means includes sections extending horizontally in opposite directions from said riser to present opposite ends disposed remotely from the riser, there being a spray header disposed at each of said opposite ends of the sections for spraying cleansing fluid about the interior of the tank.
 4. Structure as set forth in claim 1, wherein said coupling means includes a fitting between said riser and conduit means sections, and between said conduit means sections and the spray means; the fitting having larger diameter ends for loosely receiving corresponding ends of said riser, said conduit means and said spray means, said ends of the fittings and corresponding ends of the riser, conduit means and header having aligned holes therein; and pins having straight segments loosely fitting in said aligned holes to couple said fittings to said riser, said conduit means and said header.
 5. Structure as set forth in claim 4, wherein said fitting between said riser and said conduit means is a tee fitting having three enlarged ends receiving adjacent ends of said riser and said conduits.
 6. Structure as set forth in claim 1, wherein said coupling means includes a fitting between said riser and conduit means sections, and between said conduit means sections and the spray means; the fitting having larger diameter ends for loosely receiving corresponding ends of said riser, said conduit means and said spray means, said ends of the fittings and corresponding ends of the riser, conduit means and header having aligned holes therein; and pins having straight segments loosely fitting in said aligned holes to couple said fittings to said riser, said conduit means and said header, said pins having curved segments frictionally engaging the outer surfaces of said fittings to hold said pins in said aligned holes.
 7. Structure as set forth in claim 1, including means for releasably securing said conduit means to said support means to hold the self-cleaning structure in position.
 8. Structure as set forth in claim 7, wherein said support means is configured to loosely surround said conduit means, said conduit means and support having aligned holes therein, and means securing the conduit means to the support means in the form of pins having straight segments loosely fitting in said aligned holes yet allowing fluid flow therethrough.
 9. Structure as set forth in claim 7, wherein said support means is configured to loosely surround said conduit means, said conduit means and support having aligned holes therein, and means securing the conduit means to the support means in the form of pins having straight segments loosely fitting in said aligned holes yet allowing fluid flow therethrough, and curved segments frictionally engaging the outer surfaces of said supports to hold said pins in said holes.
 10. Structure set forth in claim 1, wherein said supports are disposed to hold said conduit means in offset relation to a transverse centerline of saId tank.
 11. Structure as set forth in claim 1, wherein the coupling means includes first and second end members, the first end member having an inside diameter sufficiently larger than the outside diameter of the second end member to allow flow of fluid therebetween; vertically aligned holes in the first and second end members and pin means loosely fitting in said holes for releasably holding the coupling together and allowing the conduit means to drain through the lower most holes.
 12. In combination with a mobile transport tank having an access opening in the top thereof and adapted to carry milk or like liquid, self-cleaning structure for cleansing the interior of the tank by use of cleansing fluid from an external source, said structure comprising: a riser adapted to be connected to the external source of cleansing fluid and extending downwardly, into the interior of the tank; conduit means communicating with said riser and extending in a generally horizontal disposition to distribute the cleansing fluid along a substantial length of the tank with a remote end of the conduit means spaced from said riser, said conduit means comprising sections of a length facilitating insertion and removal thereof through the access opening; support means permanently affixed to the interior wall of the tank and removably receiving said conduit means to hold the latter in said generally horizontal disposition thereof; and coupling means for defining a joint between said conduit means and said riser, for releasably coupling said conduit means to said riser in a relatively loose tolerance allowing free flow of the cleansing fluid through said joint to completely purge and clean the joint whereby said structure is sufficiently self-cleaning to remain in the tank after the latter is filled with milk or like liquid.
 13. Structure as set forth in claim 12, wherein said conduit means is disposed with a remote end spaced from said riser, there being a spray header coupled to said remote end of the conduit means and in communication therewith, said header being rotatable in a generally horizontal plane in response to flow of cleansing fluid thereto from said conduit means and having apertures therein for spraying the cleansing fluid about the interior of the tank.
 14. Structure for cleansing the interior of a mobile transport tank having an access opening in the top thereof and adapted to carry milk or like liquid, by use of cleansing fluid from an external source, said structure comprising: a riser adapted to be connected to the external source of cleansing fluid and extending downwardly into the center of the tank in sealed relationship thereto to deliver cleansing fluid to the interior; conduit means coupled to and communicating with said riser and extending in opposite directions along a substantial length of the tank with opposite remote ends of the conduit means spaced from said riser, said conduit means comprising sections of a length facilitating insertion and removal thereof through the access opening; support means adapted to be permanently affixed to the interior wall of the tank and removably receiving said conduit means to hold the latter in said generally horizontal position thereof; and a pair of spray headers coupled to said remote ends of the conduit means and in communication therewith, said headers being rotatable in a generally horizontal plane in response to flow of cleansing fluid thereto from said conduit means and having apertures therein for spraying the cleansing fluid about the interior of the tank. 